The present invention relates generally to vessel harvesting and in particular to an improvement over existing endoscopic vessel harvesting techniques and devices.
Endoscopic harvesting of vessels is well known in the surgical field and has been the subject of a great deal of recent technological advancement. Typically, the harvesting of vessels is performed so that the vessels can then be used for procedures such as Cardio Artery Bypass Grafting (CABG). In this procedure the saphenous veins of the legs are harvested for subsequent use in the CABG surgery.
Devices and methods for such vessel harvesting are well known and have been described in numerous publications including U.S. Pat. No. 5,667,480 issued Sep. 16, 1997 and U.S. Pat. No. 5,722,934 issued Mar. 3, 1998 to Knight et al, both of which are incorporated herein by their reference. The devices and methods of these patents are briefly described below.
In the traditional harvesting devices, there is provided a hollow shaft connected to a concave headpiece located at the distal end of the shaft which provides a workspace. An endoscope is typically inserted in the shaft so that the surgeon may view workspace. The leading edge of the headpiece is used for dissecting the vessel from the surrounding tissue. The device may also have guide rails located on the underside of the device which allow for the entry of other devices such as dissectors, ligation tools, and cutting tools into the workspace.
The traditional method for removal of a vessel section is as follows. Initially an incision is made and the vessel is located. Then, the vessel is dissected form the surrounding tissue using the leading edge of the headpiece of the device to separate the tissue from the vessel. At this time there is sufficient workspace created around the vessel so that other instruments can be inserted into the incision via the guide rails located on the underside of the device. These instruments include ligation tools for securing side branch vessels, a vessel dissector for performing a more complete dissection of the vessel, which is to be removed, and laproscopic scissors for the transection of both the side branch vessels and the vessel which is to be removed.
Of the known devices and methods for removal of vessels there remains one constant problem. The problem is that to perform each an every one of the side branch ligation and transactions, extra tools must be inserted along the guide rails of the device through the original incision. Often times this means that to perform a single transection of a side branch vessel three tools must be inserted in succession into the body. The various tools include, a dissector to dissect the side branch from the surrounding tissue, a ligation tool to clamp the side branch vessel and the vessel to be removed, and a cutting tool to perform the transection. Additionally, the harvesting device remains in the body throughout the procedure.
This requirement of inserting the tools in succession and exchanging one tool for another to perform each step of the operation requires extra time, this in turn can be a drain on the individual surgeons resources. Further, because of this increased amount of time, which the surgeon requires to perform the operation, the stress on the patient is increased. Minimization of patient stress is naturally a concern during any surgical procedure. Therefore, the elimination of some or all of the time extending tool exchanges would greatly benefit not only the patient but the surgeon as well.
The present invention is directed to solving the shortcomings of known vessel harvesting devices, by providing a superior vessel harvesting device, promoting efficient removal of vessels, and limiting the stress on patients. The objects of the present invention are the minimization of the tool exchanges, increased efficiency of operation, minimization of patient stress, and increased ease of the overall harvest operation. Further, the present invention pertains to a device having a means for capturing side branch vessels so that they may be ligated and transected.
Accordingly a vessel harvesting device is provided. The endoscopic device comprises a shaft having a lumen for insertion of an endoscope therethrough, a headpiece defining a workspace and disposed at a distal end of the shaft, a handle disposed at a proximal end of the shaft, a plunger disposed at the distal end of the shaft and movable between a retracted and extended position, wherein in the extended position the plunger interacts with at least a portion of the headpiece to capture a vessel there between, an actuation means for moving the plunger between the retracted and extended positions, and a ligation means for cauterizing the vessel captured between the plunger and the portion of the headpiece.
The vessel harvesting device preferably comprises a transection means for transecting the cauterized vessel, wherein the portion of the headpiece comprises a hook projecting into the workspace.
The headpiece preferably comprises side projections extending from an edge of the headpiece and projecting towards the plunger of the headpiece, the side projections facilitating the positioning of the vessel for capture.
The ligation means preferably comprises the plunger having at least two electrodes of opposite polarity separated by at least one dielectric layer, the electrodes being energized with RF energy to cauterize the captured vessel.
The transection means preferably comprises the plunger having an extendable knife separated from each of the at least two electrodes by a dielectric layer, wherein the at least two electrodes comprises a first and second electrode and one of the first and second electrodes is a knife separated from the other electrode by at least one dielectric layer.
The portion of the headpiece preferably comprises a slidable hook projecting into the workspace, movable from an extended to a retracted position, wherein the hook interacts with the plunger to capture the side branch when in the extended position.
The vessel harvesting device further preferably comprises a control rod actuation means for moving the slidable hook between the extended and retracted positions, wherein the control rod actuation means comprises a flexible control rod operably connected to the slidable hook for sliding the slidable hook between the extended and retracted positions, the control rod having an extension stop which limits the travel of the slidable hook and also having a capturing means which prevents the slidable hook and the control rod from entering the workspace, and wherein the control rod is formed of a flexible material conforming to the shape of the headpiece while transitioning from the retracted to the extended position and maintaining its conformance with the headpiece when in the extended position.
Also provided is a method of removing a vessel utilizing the above-described device. The method of harvesting a vessel comprising the steps of providing a vessel harvesting device comprising a shaft having a lumen for insertion of an endoscope therethrough, a transparent headpiece defining a workspace and disposed at a distal end of the shaft, a handle disposed at a proximal end of the shaft, a plunger disposed at the distal end of the shaft and movable between a retracted and extended position, wherein in the extended position the plunger interacts with at least a portion of the headpiece to capture a vessel therebetween, an actuation means for moving the plunger between the retracted and extended positions, a ligation means for cauterizing the side branch, and a transection means for transecting the cauterized side branch, locating a vessel to be harvested, making an incision to expose the vessel, inserting the vessel harvesting device into the patient through the incision, dissecting the vessel from the surrounding tissue with the vessel harvesting device to expose a side branch of the vessel, actuating the plunger in the distal direction to capture the side branch between the plunger and the portion of the headpiece, applying RF energy to cauterize the captured side branch, transecting the cauterized side branch using the transection means, ligating and transecting the vessel, and removing the vessel.
The step of ligating the side branch preferably comprises applying RF energy to the side branch using first and second electrodes, wherein the first and second electrodes are of different polarity and are housed in the plunger.
The step of transecting the side branch preferably comprises extending a knife housed in the plunger towards the distal end of the device.
The step of capturing preferably comprises placing the headpiece over the side branch and extending the plunger in the distal direction to allow the side branch to be compressed between the plunger and the portion of the headpiece.
The step of transecting the side branch preferably comprises advancing a knife housed in the lower jaw towards the distal end of the device subsequent to the ligation of the side branch vessel.
The step of actuating preferably comprises extending a slidable hook in the distal direction prior to extension of the plunger.
This use of the plunger and the ligation and transection means located therein limits the number of tools which must be inserted into the incision. Further, by having the ligation and transection means located in the plunger the procedure is more easily performed, and with a minimum of stress to the patient and in a decreased amount of time.